Adolescents are at increased risk for HIV/STI acquisition. Although many adolescents (47%) are sexually experienced before graduating high school [1], a recent survey showed 60 percent wish they had waited [2] and some are choosing to abstain from further sexual activity. Given that abstinence research typically focuses on adolescents without sexual experience (virgins), very little is known about abstinence among sexually experienced youth (secondary abstainers). Although in recent years some exploratory research has been conducted to begin understanding secondary abstinence, few studies have included significant numbers of young African-American females, a population at increased risk for HIV/STIs [3]. Therefore the aims of the proposed study are to understand how young sexually experienced African- American females conceptualize secondary abstinence, motivations for becoming abstinent, and barriers to successful adoption of secondary abstinence. Further, the proposed study seeks to explore dissonance between interest in becoming abstinent and continued sexual activity in order to develop a theory of barriers to adopting secondary abstinence. The proposed investigation uses a mixed-methods approach to achieve study aims and employs a sequential exploratory design consisting of two phases. This research design is suited for investigating phenomena about which little is known as well as theory development and testing. During the first phase, in-depth interviews will be conducted with young sexually experienced African- American females who are interested in becoming abstinent and are participating in an HIV-risk reduction intervention, in order to develop an emergent theory of barriers to adopting secondary abstinence. During the second phase the emergent theory from the first phase will be tested through secondary analysis of data collected from 701 sexually experienced African-American adolescent females, ages 14-20, participating in the larger intervention study. Findings from this study will permit identification of cognitive and behavioral skills needed to successfully adopt secondary abstience and wll be used to develop the abstinence component of new or strengthen existing comprehensive HIV/STI risk reduction programs. Such gains will support the NIMH Division of AIDS and Health and Behavior Research goal to develop and dissmeinate behavioral interventions that prevent HIV transmission. PUBLIC HEALTH RELEVANCE: Disproportionate HIV/STI rates among young African-American women have made prevention efforts high priority. Secondary abstinence is one prevention strategy, yet little is known about this phenomenon. Findings from this study will inform the development of theory-based interventions that adequately address the needs of this vulnerable population.